Extraordinary claims in the literature on high-intensity interval training (HIIT): IV. Is HIIT associated with higher long-term exercise adherence?

Maintenance of time-restricted eating and high-intensity interval training in women with overweight/obesity 2 years after a randomized controlled trial

Time-restricted eating (TRE) and high-intensity interval training (HIIT) improve cardiometabolic health in individuals with overweight/obesity, with high adherence rates in supervised settings. Long-term maintenance of TRE and HIIT in real-world settings is unknown. In our previous TREHIIT trial, 131 women (body mass index (BMI) ≥ 27 kg/m2) were randomized to 7 weeks of TRE (eating window 10-h/day), HIIT (3 sessions/week), a combination (TREHIIT), or no intervention (CON). We investigated self-reported continuation of TRE and/or HIIT after 2 years. Fifty-nine participants (39.0 years (standard deviation (SD) 6.1), BMI 30.7 kg/m2 (SD 4.2)) attended the follow-up. Of those who completed the 7-week TRE or HIIT intervention, 46% maintained TRE and 45% continued HIIT for 2 years. There were no statistically significant (at p < .01) between-group differences in cardiometabolic outcomes, but non-significant lower body mass in HIIT (-4.2 kg, 95% confidence interval (CI), -7.7 to -0.7, p = .019) and visceral fat in TREHIIT (-18 cm2, CI, -33 to -4, p = .015) versus CON. After 2 years, HIIT and TREHIIT had ~ 4 kg lower fat mass and ~ 20 cm² lower visceral fat (both p < .001) compared with baseline. A short-term TRE and HIIT intervention may promote long-term lifestyle changes and health benefits. Future studies should collect objective adherence data to understand long-term maintenance of TRE and HIIT.

Efficacy of high-intensity interval training in individuals with type 2 diabetes mellitus: An umbrella review of systematic reviews and meta-analyses

High-intensity interval training (HIIT) has gained attention as a potentially effective alternative to traditional exercise modalities for individuals with type 2 diabetes mellitus (T2DM). Previous studies have evaluated this exercise strategy with various regimens, comparator groups and outcomes, limiting the generalisability of findings. We performed a novel umbrella review to generate an up-to-date synthesis of the available evidence regarding the effect of HIIT on glycaemic control and other clinically relevant cardiometabolic health outcomes in individuals with T2DM, as compared with traditional moderate-intensity continuous training (MICT) and/or non-exercise control (CON). This umbrella review followed the Preferred Reporting Items for Overviews of Reviews guideline. Seven databases were searched until August 2024. Systematic reviews with meta-analyses comparing HIIT with MICT and/or CON were included. Literature search, data extraction and methodological quality assessment (A MeaSurement Tool to Assess systematic Reviews 2 [AMSTAR-2]) were conducted independently by two reviewers. Ten systematic reviews with meta-analyses, encompassing 76 primary studies and 2954 unique participants, met the inclusion criteria. The data indicated that HIIT significantly improves glycosylated haemoglobin and cardiorespiratory fitness compared with CON (weighted mean difference [WMD]: -0.83% to -0.39% and 3.35-6.38 mL/kg/min) and MICT (WMD: -0.37% to -0.07% and 1.68-4.12 mL/kg/min) in individuals with T2DM. HIIT is also effective in improving other glycaemic parameters, including fasting blood glucose, fasting blood insulin and HOMA-IR. Improvement in body composition, lipid profiles and blood pressure has also been observed following HIIT. Most systematic reviews received moderate to low AMSTAR-2 score. This umbrella review supports HIIT as an efficacious exercise strategy for improving glycaemic control and certain relevant cardiometabolic health outcomes in individuals with T2DM. Our findings offer a comprehensive basis that may potentially contribute to informing physical activity recommendations for incorporating HIIT into T2DM management strategies.

High Intensity Interval Training and Arterial Hypertension: Quality of Reporting

The benefits of exercise have been well described for the treatment of hypertension. Poor reporting quality impairs quality appraisal and replicability. High intensity interval training (HIIT) has been shown to be an effective alternative to traditional aerobic exercise in patients with hypertension. We evaluated the completeness of reporting of randomized controlled trials (RCTs) with HIIT for hypertension and to compare both exercise modes in reporting quality. RCTs of HIIT with a minimum duration of 6 weeks in adults with at least high normal blood pressure (≥130 mmHg/≥85 mmHg) were evaluated using the Consensus on Exercise Reporting Template (CERT). Nine RCTs conducting HIIT in hypertensive patients (N=718; 51.8 years) were evaluated. A mean of 62.6% of items were sufficiently described, compared with 49.2% in moderate intensity training interventions. Exercise dose was adequately reported in 8 out of 9 studies. Only one study reported information on adverse events. In a small sample of RCTs with HIIT in patients with hypertension we found a better reporting quality than in moderate intensity training interventions. However, reporting completeness is not optimal for a good replicability in clinical practice. The lack of reporting of adverse events in interventions using high intensities is particularly unfavourable.

Effects of practical models of low-volume high-intensity interval training on glycemic control and insulin resistance in adults: a systematic review and meta-analysis of randomized controlled studies

Objectives

The aim of this systematic review and meta-analysis was to investigate the effects of practical models of low-volume high-intensity interval training protocols (LV-HIIT) on glucose control and insulin resistance compared with moderate-intensity continuous training (MICT) protocols and no-exercise controls (CON).

Methods

Four databases (PubMed, Web of Science, Scopus, and Cochrane Library) were searched for randomized controlled studies conducted using LV-HIIT interventions (HIIT/SIT protocols involving ≤ 15 min of intense training, within a session lasting ≤ 30 min; < 30 s all-out sprint for SIT additionally). The inclusion criteria required glucose and insulin resistance markers to be evaluated pre- and post-intervention among adults who were not trained athletes.

Results

As a result, twenty studies were included, and meta-analyses were conducted using sixteen studies employing HIIT protocols. Compared with CON, LV-HIIT with reduced intensity and extended interval duration significantly improved fasting glucose (FPG) (mean difference (MD) in mg/dL=-16.63; 95% confidence interval (CI): -25.30 to -7.96; p<0.001) and HbA1c (MD=-0.70; 95% CI: -1.10 to -0.29; p<0.001). Greater improvements were found in participants who were overweight/obese or having type 2 diabetes (T2D). FPG decreased with every additional second of interval duration (β;=-0.10; 95% CI: -0.19 to -0.00; p=0.046). FPI (β;=-0.65; 95% CI: -1.27 to -0.02; p=0.042) and HOMA-IR (β;=-0.22; 95% CI: -0.36 to -0.09; p=0.001) decreased with every additional minute of interval duration per session. HOMA-IR also decreased with every additional minute of weekly interval duration (β;=-0.06; 95%CI: -0.08 to -0.04; p<0.001). Compared with MICT, LV-HIIT was more effective in improving insulin sensitivity (SMD=-0.40; 95%CI: -0.70 to -0.09; p=0.01), but there were no differences in FPG, FPI, HbA1c or HOMA-IR (p>0.05). The effect of LV-HIIT on FPI was larger compared with MICT among individuals who lost weight.

Conclusion

Conclusively, a practical model of LV-HIIT with reduced intensity and extended interval was effective in improving glucose control and its effects were similar to MICT. Greater improvements were found in individuals with overweight/obesity or T2D in protocols with longer intervals or accumulated interval duration per session/week. More large-scale, randomized controlled studies with similar intervention protocols in a wide range of population are warranted to confirm these important results.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024516594.

Negotiating a physically active life in tune with ageing: a grounded theory study of older persons' experiences of participating in high-intensity interval training

BACKGROUND

Physical activity and exercise are promoted worldwide as effective interventions for healthy ageing. Various exercise initiatives have been developed and evaluated for their efficacy and effectiveness among older populations. However, a deeper understanding of participants' experiences with these initiatives is crucial to foster long-term activity and exercise among older persons.

METHODS

A constructivist grounded theory study was conducted to explore the experiences of older persons participating in a supervised group supramaximal high-intensity training (HIT) programme. Four focus groups were held, involving 28 persons aged 65 to 78. The focus groups were analysed inductively, followed by an iterative process of abstraction, abduction, and theory generation using a constant comparative method. A conceptual framework comprising three theoretical concepts-stereotype embodiment, ageist practices, and self-efficacy-was employed during the abductive phase as an analytical lens.

RESULTS

The core category of our grounded theory, Negotiating a physically active life in tune with ageing, encapsulates the complex processes and actions influencing older persons as they engage in physical activities in their daily lives and in relation to HIT. This core category was created from the conceptual framework and the four categories: Grit in the moment and overall life, Empowered by the training group, Navigating one's physically active self, and Committing to exercise for duty and pleasure. Participants reported feeling invigorated by the exercise, enjoying the challenge, and valuing the group setup for its social connectedness and structure. The generated theory illustrates how participants' engagement with physical activity and exercise is shaped by various perspectives accumulated over their lifespan. The findings provide a plausible explanation of how participation in HIT groups can challenge negative age stereotypes and ageist practices while enhancing self-efficacy for high-intensity exercise.

CONCLUSIONS

Our grounded theory underscores that physical activity and exercise should be regarded as multifaceted processes, which must be considered when promoting physical activity initiatives for older persons. By considering the older person and societal norms and values, we can gather knowledge to design physical exercise interventions that are not only effective but also enjoyable and capable of transforming how individuals perceive themselves as exercising persons.

Effects of Physical Exercise Breaks on Executive Function in a Simulated Classroom Setting: Uncovering a Window into the Brain

Acknowledging the detrimental effects of prolonged sitting, this study examined the effects of an acute exercise break during prolonged sitting on executive function, cortical hemodynamics, and microvascular status. In this randomized crossover study, 71 college students completed three conditions: (i) uninterrupted sitting (SIT); (ii) SIT with a 15 min moderate-intensity cycling break (MIC); and (iii) SIT with a 15 min vigorous-intensity cycling break (VIC). Behavioral outcomes, retinal vessel diameters (central retinal artery equivalents [CRAE], retinal vein equivalents [CRVE], arteriovenous ratio [AVR]), cortical activation, and effective connectivity were evaluated. Linear mixed models identified significant positive effects of exercise conditions on behavioral reaction time (RT), error rate, and inverse efficiency score (β = -2.62, -0.19, -3.04: ps < 0.05). MIC and VIC conditions produced pre-to-post-intervention increases in CRAE and CRVE (β = 4.46, 6.34), frontal activation, and resting-state and task-state causal density (β = 0.37, 0.06) (ps < 0.05) compared to SIT; VIC was more beneficial for executive function and neurobiological parameters. The effect of AVR on average RT was mediated through task-based causal density (indirect effect: -0.82). Acutely interrupting prolonged sitting improves executive function, microvascular status, and cortical activation and connectivity, with causal density mediating the microvascular-executive function link.

Criterion validity of a newly developed Apple Watch app ('MVPA') compared to the native Apple Watch 'activity' app for measuring criterion moderate intensity physical activity

Introduction

Many people fail to meet physical activity guidelines. One possible solution is wearable technology. Yet it is unclear if popular devices such as the Apple Watch can accurately measure intensity, which is a cornerstone of physical activity guidelines. We developed a bespoke Apple Watch app based on the use of relative intensity (%HRR), with the aim to determine if the bespoke app measures 'moderate' intensity more accurately compared to the native Apple Watch Activity app, using % oxygen consumption reserve (%VO2R) as the criterion.

Methods

Seventy-four participants (18-65 years) attended the laboratory twice. During Visit 1, they completed medical screening, and measurements of resting heart rate, maximal oxygen consumption, and maximal heart rate on a motorised treadmill. During Visit 2, participants completed 5-minute treadmill bouts starting at 3.5 km.h-1, increasing by 0.5 km.h-1 until the bespoke app recorded 3 minutes at ≥40%HRR, and the native app recorded 5 minutes of 'exercise'. Oxygen consumption and heart rate were recorded. Bayesian posterior distributions were used to compare the two apps.

Results

At the walking speed that the native app recorded exercise, the mean (95% HDI) %VO2R was 33 (31-36)%, which is below moderate relative intensity (40%HRR). This is compared to a mean (95% HDI) of 43 (40-44)% for our bespoke app.

Conclusion

The bespoke app measured relative moderate intensity more accurately compared to the native app when compared to the %VO2R criterion. Exercise guidelines and wearable devices should incorporate relative measures of physical activity to better individualise monitoring and prescription.

Effects of high-intensity interval and moderate-intensity continuous training on ambulatory blood pressure and cardiovascular outcomes in older adults with hypertension (HEXA Study): study protocol for a randomised trial

INTRODUCTION

Approximately two-thirds of Brazilian older adults have hypertension. Aerobic training is the first-line non-pharmacological therapy for hypertension. However, the effects of different aerobic training approaches on ambulatory blood pressure in older adults are uncertain. Here, we present the study protocol for the HEXA Study, which aims to investigate the effects of high-intensity interval (HIIT) and moderate-intensity continuous training (MICT) on 24-hour ambulatory blood pressure and cardiovascular outcomes in older adults with hypertension.

METHODS AND ANALYSIS

This is a single-centre, randomised, three-arm, parallel superiority trial with a 1:1:1 ratio. The trial is conducted with blinded outcome assessors and statistical analysts. 66 inactive older adults with hypertension aged 60-80 years without a history of major adverse cardiovascular events will be randomly assigned to one of the following groups: (1) HIIT (3 months; 3× week); (2) MICT (3 months; 3× week); (3) health education programme (control; 3 months; 1× week). Exercise training sessions involve rating of perceived exertion-based outdoor moderate walking, brisk walking and/or jogging. The primary outcome is 24-hour ambulatory blood pressure. Secondary cardiovascular outcomes are resting blood pressure, cardiorespiratory fitness, pulse wave velocity, carotid intima-media thickness, heart rate variability and cardiac function/structure. All outcomes are measured at baseline and after a 3-month period. In addition, feelings of pleasure/displeasure, adherence and safety are reported.

ETHICS AND DISSEMINATION

All procedures were approved by the Research Ethics Committee of the Onofre Lopes University Hospital (protocol, CAAE 07191019.8.0000.5292) and are executed in compliance with the Declaration of Helsinki. Additionally, the procedures adhered to Resolution 466/2012 issued by the Brazilian National Health Council for research involving human subjects.

TRIAL REGISTRATION NUMBER

Brazilian Registry of Clinical Trials (ID: RBR-4ntszb).

Immersive Virtual Reality Decreases Work Rate and Manipulates Attentional Focus During Self-Regulated Vigorous Exercise

To determine the effect of immersive virtual reality use on finishing time of a vigorous-intensity self-regulated exercise task, and on relevant psychological variables. Healthy untrained adults (N = 21; 10 men/11 women; age = 22.9 ± 7.2 years; BMI = 24.0 ± 4.5 kg/m2) completed 1500-m exercise bouts on a rowing ergometer in a counterbalanced and randomized order, with and without use of a headset-delivered virtual reality fitness program. Heart rate, rating of perceived exertion, affective valence, and attentional focus were collected every 300 m, in addition to finishing time. Data were analyzed with repeated measures as appropriate. Intensity of both exercise bouts was considered vigorous according to heart rate results (>77% maximal heart rate). Finishing time was faster in the control condition (449.57 ± 82.39 s) than in the virtual reality condition (463.00 ± 91.78 s), p = .007. Compared to the control condition, the virtual reality condition was characterized by a more external attentional focus (52.38 ± 18.22 vs. 38.76 ± 17.81, p < .001). No differences were observed for remaining variables as a result of condition (p > .05 for all). When a headset-delivered VR program was used during a self-regulated vigorous-intensity exercise task, participants were 13.6 seconds (~3%) slower than in a control condition. Attentional focus was manipulated to be more external with VR use, which may have ultimately distracted from the exercise objective. Recommendations for selecting an appropriate virtual reality experience for a given exercise task are discussed.

High-intensity interval training for improving cardiometabolic health in children and adolescents: An umbrella review of systematic reviews

High-intensity interval training (HIIT) is an emerging exercise strategy to improve health and fitness, but previous studies have evaluated HIIT interventions across different populations and outcomes. This review aimed to comprehensively synthesize published evidence on the effects of HIIT on key cardiometabolic health parameters in children and adolescents. We searched seven databases until February 2024. Systematic reviews were eligible if they 1) compared HIIT and active/non-active control conditions with meta-analysis, 2) examined cardiorespiratory fitness, body composition and cardiometabolic risk biomarkers, and 3) examined children and adolescents. We included 18 systematic reviews with meta-analysis, including 223 original studies and 13,900 unique participants. HIIT is effective for cardiorespiratory fitness in children and adolescents with diverse health and weight status (median standardized mean difference [SMD] = 0.75). Improvements in body composition and several cardiometabolic risk biomarkers, including systolic blood pressure (median SMD = -0.40), diastolic blood pressure (median SMD = -0.22), triglyceride (median SMD = -0.30), low-density lipoprotein cholesterol (median SMD = -0.90), and high-density lipoprotein cholesterol (median SMD = 0.34), have also been observed following HIIT, with a notably more pronounced effect in youth with overweight/obesity or metabolic disorders. Our umbrella review supports the effectiveness of HIIT in enhancing cardiometabolic health, suggesting its integration into physical activity promotion programmes in schools and communities.

High-Intensity Interval Training vs. Medium-Intensity Continuous Training in Cardiac Rehabilitation Programs: A Narrative Review

Exercise-based cardiac rehabilitation (ExCR) programs are essential for patients diagnosed with cardiac diseases. Studies have shown that they aid in the rehabilitation process and may even facilitate a return to previous cardiorespiratory fitness. Also, patients who enroll and follow such programs have shown a lower rate of complications and mortality in the long run. The results vary depending on the type of program followed and the degree of debilitation the disease has caused. Therefore, in order to obtain optimal results, it is ideal to tailor each ExCR program to the individual profile of each patient. At the moment, the two most studied and employed training types are medium-intensity continuous training (MICT) and high-intensity interval training (HIIT). For most of the time, MICT was the first-choice program for patients with cardiovascular disease. In recent years, however, more and more studies have pointed towards the benefits of HIIT and how it better aids patients in recovering their cardiovascular fitness. Generally, MICT is more suited for patients with a severe degradation in functional capacity and who require a higher degree of safety (e.g., elderly, with a high number of comorbidities). On the other hand, while HIIT is more demanding, it appears to offer better outcomes. Therefore, this review aimed to summarize information from different publications on both types of training regimens in ExCR and assess their utility in current clinical practice.

"But will they do it?" Challenging assumptions and incivility in the academic discourse on high-intensity interval training

Debate over whether to promote high-intensity interval training (HIIT) in public-health contexts has centred on assumptions that people will have negative psychological responses to HIIT, leading to poor adoption and adherence. We challenge these assumptions through reviews of (1) studies that have measured psychological responses to HIIT and (2) studies that have measured adherence to HIIT protocols in supervised or unsupervised settings. Overall, the evidence suggests that HIIT is just as enjoyable as moderate-intensity continuous training (MICT). In supervised situations, on average, adherence is similarly high for HIIT and MICT (>89%). In unsupervised situations, adherence is similarly lower for both HIIT and MICT (<69%). Based on these findings, we recommend that attention be directed toward improving behaviour-change and maintenance for all types of exercise. Resources are better spent addressing fundamental questions about exercise initiation and adherence, than perpetuating a vitriolic and uncivil debate over the value of HIIT versus MICT. We discuss how debate, incivility, and bullying undermine scientific progress and we issue a call for respectful, civil dialogue in academic HIIT discussions. We conclude with recommendations that can be used by all members of the scientific community to practice, champion, and defend civil discourse.

Efficacy of Interval Training in Improving Body Composition and Adiposity in Apparently Healthy Adults: An Umbrella Review with Meta-Analysis

BACKGROUND

Although the efficacy of interval training for improving body composition has been summarized in an increasing number of systematic reviews in recent years, discrepancies in review findings and conclusions have been observed.

OBJECTIVE

This study aims to synthesize the available evidence on the efficacy of interval training compared with moderate-intensity continuous training (MICT) and nonexercise control (CON) in reducing body adiposity in apparently healthy adults.

METHODS

An umbrella review with meta-analysis was performed. A systematic search was conducted in seven databases (MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science) up to October 2023. Systematic reviews with meta-analyses of randomized controlled trials (RCTs) comparing interval training and MICT/CON were included. Literature selection, data extraction, and methodological quality assessment (AMSTAR-2) were conducted independently by two reviewers. Meta-analyses were performed using a random-effects model. Subgroup analyses were conducted based on the type of interval training [high-intensity interval training (HIIT) and sprint interval training (SIT)], intervention duration, body mass index, exercise modality, and volume of HIIT protocols.

RESULTS

Sixteen systematic reviews, including 79 RCTs and 2474 unique participants, met the inclusion criteria. Most systematic reviews had a critically low (n = 6) or low (n = 6) AMSTAR-2 score. Interval training demonstrated significantly greater reductions in total body fat percent (BF%) compared with MICT [weighted mean difference (WMD) of - 0.77%; 95% confidence interval (CI) - 1.12 to - 0.32%] and CON (WMD of - 1.50%; 95% CI - 2.40 to - 0.58%). Significant reductions in fat mass, visceral adipose tissue, subcutaneous abdominal fat, and android abdominal fat were also observed following interval training compared to CON. Subgroup analyses indicated that both HIIT and SIT resulted in superior BF% loss than MICT. These benefits appeared to be more prominent in individuals with overweight/obesity and longer duration interventions (≥ 12 weeks), as well as in protocols using cycling as a modality and low-volume HIIT (i.e., < 15 min of high-intensity exercise per session).

CONCLUSIONS

This novel umbrella review with large-scale meta-analysis provides an updated synthesis of evidence with implications for physical activity guideline recommendations. The findings support interval training as a viable exercise strategy for reducing adiposity in the general population.

Low-volume combined aerobic and resistance high-intensity interval training in type 2 diabetes: a randomised controlled trial

Objective

The objective of this study was to compare the effects of novel, time-efficient, low-volume combined aerobic and resistance high-intensity interval training (C-HIIT), and current exercise guidelines (210 min/week of combined moderate-intensity continuous training (C-MICT)), with waitlist control (CON) on glycaemic control in people with type 2 diabetes mellitus (T2D).

Methods

Sixty-nine low-active people with T2D were randomised to 8 weeks of supervised C-HIIT (78 min/week), supervised C-MICT (210 min/week), or waitlist CON. Those in waitlist CON were re-randomised to supervised C-HIIT/C-MICT at week 8. Following 8 weeks of supervised training, participants completed 10 months of self-directed exercise. Outcomes were assessed at baseline, week 8 and month 12. Participants in waitlist CON were only included in the exercise groups for the month 12 analysis. Analyses were completed using intention-to-treat analysis of covariance (n=69; week 8) and linear mixed modelling (n=63; month 12).

Results

Compared with CON, at week 8, HbA1c decreased in C-HIIT (adjusted mean difference: -0.7% (95% CI -1.3, -0.2%)) and C-MICT (-1.2% (-1.9, -0.6%)). There were also improvements in C-HIIT and C-MICT versus CON at week 8 for fat mass (-1.9 (-3.1, -0.6) and -1.5 (-2.6, -0.4) kg, respectively), lean mass (1.5 (0.8, 2.3) and 0.9 (0.1, 1.7) kg), and exercise capacity (124 (77, 171) and 49 (5, 93) s). At month 12, adherence was low, and most measures returned to baseline.

Conclusions

Low-volume C-HIIT (78 min/week) and C-MICT (210 min/week) improved glycaemic control, body composition and exercise capacity similarly over 8 weeks in people with T2D. However, at month 12, improvements were not maintained following self-directed exercise. Regardless, these data suggest that supervised low-volume C-HIIT is a time-efficient and effective strategy for improving outcomes in T2D.

One-HIIT wonder: Can music make high-intensity interval training more pleasant?

The use of music as an aid to recovery during and after exercise is an area of growing scientific interest. We investigated the effects of in-task, asynchronous music and respite-active music (i.e., music used for active recovery in between high-intensity exercise bouts) on a range of psychological, psychophysical and psychophysiological outcomes. Participants (N = 28; 14 females) made five laboratory visits for: (a) pre-test/familiarisation; (b) fast-tempo music during supramaximal exercise bouts and medium-tempo music during active-recovery periods; (c) fast-tempo music during exercise and no music during recovery; (d) no music during exercise and medium-tempo music during recovery; and (e) a no-music (throughout) control. A cycle ergometer-based HIIT protocol comprising 6 × 60-s bouts at 100% Wmax with 75-s active recovery was administered. Measures were taken at the end of supramaximal bouts and active recovery periods (RPE, state attention, core affect, state motivation), then upon cessation of the protocol (remembered pleasure and exercise enjoyment). Heart rate and heart rate variability (HRV) measures were taken throughout. The music manipulations only had an effect on state motivation, which was higher (p = 0.036) in the fast tempo-medium tempo condition compared to no-music control (Cohen's d = 0.49), and the SDNN component of HRV, which was lower (p = 0.007) in the fast-tempo-no-music condition compared to control (Cohen's d = 0.32). Collectively, the present findings do not support any of the study hypotheses regarding the music-related manipulations, and do not concur with the findings of related studies (e.g., Karageorghis et al., 2021). The unexpected results are discussed with reference to extant theory, and recommendations are offered in regard to music-related applications.

Reduced-exertion high-intensity interval training (REHIT): a feasible approach for improving health and fitness?

In recent years, research investigating the dose-response to sprint interval training (SIT) has provided evidence that the number and duration of repetitions in a SIT session can be reduced whilst preserving the beneficial health-related adaptations. Together this research has led to the development of protocols involving minimal doses of SIT: regularly performing just two or three 20-30 s all-out sprints in a 10 min training session has been shown to elicit beneficial metabolic and cardiovascular adaptations. These SIT protocols, which we originally termed "reduced-exertion high-intensity interval training" (or REHIT), have the potential to remove many of the common barriers associated with other SIT protocols, as well as with HIT and aerobic exercise. Here, we critically review the evidence on the efficacy, feasibility and acceptability, and effectiveness of REHIT for improving health and fitness.

Applicability of a supramaximal high-intensity interval training program for older adults previously not engaged in regular exercise; analyses of secondary outcomes from the Umeå HIT Study

This analysis of secondary outcomes investigated the applicability of supramaximal high-intensity interval training (HIT) with individually prescribed external intensity performed on stationary bicycles. Sixty-eight participants with a median (min; max) age of 69 (66; 79), at the time not engaged in regular exercise were randomized to 25 twice-weekly sessions of supramaximal HIT (20-min session with 10 × 6-s intervals) or moderate-intensity training (MIT, 40-min session with 3 × 8-min intervals). The primary aim was outcomes on applicability regarding; adherence to prescribed external interval intensity, participant reported positive and negative events, ratings of perceived exertion (RPE 6-20), and affective state (Feeling Scale, FS -5-5). A secondary aim was to investigate change in exercise-related self-efficacy (Exercise Self-Efficacy Scale) and motivation (Behavioural Regulations in Exercise Questionnaire-2). Total adherence to the prescribed external interval intensity was [median (min; max)] 89 % (56; 100 %) in supramaximal HIT, and 100 % (95; 100 %) in MIT. The supramaximal HIT group reported 60 % of the positive (112 of 186) and 36 % of the negative (52 of 146) events. At the end of the training period, the median (min; max) session RPE was 15 (12; 17) for supramaximal HIT and 14 (9; 15) for MIT. As for FS, the median last within-session rating was 3 (-1; 5) for supramaximal HIT and 3 (1; 5) for MIT. Exercise-related motivation increased (mean difference in Relative Autonomy Index score = 1.54, 95 % CI [0.69; 2.40]), while self-efficacy did not change (mean difference = 0.55, 95 % CI [-0.75; 1.82]), regardless of group. This study provide support for supramaximal HIT in supervised group settings for older adults.

Enjoyment and Affective Responses to Moderate and High-Intensity Exercise: A Randomized Controlled Trial in Individuals with Subsyndromal PTSD

This crossover randomized controlled trial examined the acute psychological effects of a bout of moderate-intensity continuous aerobic exercise (MICE) and a bout of high-intensity functional exercise (HIFE), relative to a no-exercise sedentary control (SED), in participants (N = 21; 15 f; 24.7 ± 9.3 years) with subsyndromal post-traumatic stress disorder (PTSD). Affective state (Energy, Tiredness, Tension, Calmness) was assessed before (Pre), immediately after (Post 0), 20-min after (Post 20), and 40-min after (Post 40) each condition. Affective valence was assessed during each condition, and exercise enjoyment was assessed at Post 0. Enjoyment was significantly greater following HIFE and MICE relative to SED. Energy was significantly increased Post 0 HIFE and MICE but decreased Post 0 SED. Tension was reduced following all conditions and was significantly lower at Post 40 relative to Pre for HIFE, MICE, and SED. Tiredness was significantly reduced at Post 40 relative to Pre following MICE only, while Calmness was significantly lower at Post 40 relative to Pre following MICE and SED. Overall, both exercise conditions were enjoyed to a greater extent than the control, but MICE may provide greater psychological benefits with respect to Calmness and Tiredness. This study is among the first to assess acute changes in affective states relative to various exercise modes in individuals living with subsyndromal PTSD.

A Review of High-Intensity Interval Training in Heart Transplant Recipients: Current Knowledge and Future Perspectives

OBJECTIVE

This review reports how exercise-based rehabilitation strategies have developed over the past decades, and it specifically focuses on the effectiveness, safety, and implementation of high-intensity interval training (HIIT). It provides an overview of the historical progression, main research findings, and considerations surrounding HIIT as the preferred exercise modality for recipients of heart transplant (HTx).

REVIEW METHODS

The review includes a timeline of studies spanning from 1976-2023. The 2017 Cochrane systematic review on exercise-based cardiac rehabilitation in recipients of HTx serves as the main knowledge base (≥2015). Additionally, literature searches in PubMed/Medline and ClinicalTrials.gov have been performed, and all reviews and studies reporting the effects of moderate- to high-intensity exercise in recipients of HTx, published in 2015 or later have been screened.

SUMMARY

High-intensity interval training has gained prominence as an effective exercise intervention for recipients of HTx, demonstrated by an accumulation of performed studies in the past decade, although implementation in clinical practice remains limited. Early restrictions on HIIT in HTx recipients lacked evidence-based support, and recent research challenges these previous restrictions. High-intensity interval training results in greater improvements and benefits compared with moderate-intensity continuous training in the majority of studies. While HIIT is now regarded as generally suitable on a group level, individual assessment is still advised. The impact of HIIT involves reinnervation and central and peripheral adaptations to exercise, with variations in recipent responses, especially between de novo and maintenance recipients, and also between younger and older recipients. Long-term effects and mechanisms behind the HIIT effect warrant further investigation, as well as a focus on optimized HIIT protocols and exercise benefits.

High-intensity interval training and cardiorespiratory fitness in adults: An umbrella review of systematic reviews and meta-analyses

BACKGROUND

High-intensity interval training (HIIT) is characterized by repeated bouts of relatively intense exercise interspersed with recovery periods. Previous studies have evaluated this exercise strategy with various population subgroups, regimens, and comparator groups, limiting the generalizability of findings. We performed a novel umbrella review to generate an up-to-date synthesis of the available evidence regarding the effect of HIIT on cardiorespiratory fitness (CRF) in adults as compared to non-exercise control and traditional continuous forms of exercise such as moderate-intensity continuous training (MICT).

METHODS

An umbrella review was conducted in accordance with the Preferred Reporting Items for Overviews of Reviews guideline. Seven databases (MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science) were searched until February 2024. Systematic reviews with meta-analyses comparing HIIT and active/non-active control conditions were included. Literature search, data extraction, and methodological quality assessment (AMSTAR-2) were conducted independently by two reviewers.

RESULTS

Twenty-four systematic reviews with meta-analyses, representing 429 primary studies and 12 967 unique participants, met the inclusion criteria. Most of the systematic reviews received moderate-to-critically low AMSTAR-2 scores. The data showed that HIIT, including the particularly intense variant "sprint interval training" (SIT), significantly increases CRF in adults compared to non-exercise control (standardized mean difference [SMD]: 0.28 to 4.31; weighted mean difference [WMD]: 3.25 to 5.5 mL/kg/min) and MICT (SMD: 0.18 to 0.99; WMD: 0.52 to 3.76 mL/kg/min). This effect was consistently observed across specific groups of individuals (e.g., apparently healthy adults, individuals with overweight/obesity, older adults, and high-level athletes) and HIIT modalities (e.g., low-volume HIIT, whole-body HIIT, home-based HIIT, aquatic HIIT, and short SIT).

CONCLUSION

Existing evidence from systematic reviews consistently supports the effect of HIIT on enhancing CRF in adults when compared to non-exercise control and MICT. Our findings offer a comprehensive basis that may potentially contribute to informing physical activity guidelines aimed at improving CRF in the general population.

Attitudes and perceptions of cancer patients and healthcare providers towards prehabilitation: A thematic synthesis

PURPOSE

Prehabilitation, which is the process of enhancing functional capacity before undergoing surgery or other treatments, has been shown to improve cancer patients' outcomes. Patient and healthcare provider attitudes and perceptions are essential factors in the successful implementation of prehabilitation. The purpose of this systematic review is to synthesize qualitative evidence and explore the barriers and facilitators to prehabilitation implementation.

METHODS

From the earliest available date to October 2023, 7 databases (PubMed, Web of Science, Cochrane Library, Embase, CINAHL, PsycINFO, and MEDLINE) were searched for a systematic review. Data were extracted, thematically analysed, and mapped onto the Capability, Opportunity, and Motivation Model of Behaviour (COM-B). The Critical Appraisal Skills Programme (CASP) tool was used to assess the quality of the studies.

RESULTS

A total of 26 studies were included, involving 377 patients, 51 caregivers, and 156 healthcare providers. 16 factors were identified and mapped onto the COM-B model: reflective/automatic motivation, physical/social opportunity, physical/ psychological capability.

CONCLUSIONS

Patients and healthcare provides identified a lack of reflective motivation and physical opportunities as the most significant barriers to engagement in prehabilitation. Personalized approaches, social support, and healthcare providers' engagement are key factors for prehabilitation. Future research should focus on developing effective interventions to enhance the uptake and sustainability of prehabilitation.

Physical activity and mental health in individuals with multimorbidity during COVID-19: an explanatory sequential mixed-method study

OBJECTIVE

To understand the physical activity and mental health of individuals living with long-term conditions during the COVID-19 pandemic.

DESIGN

A sequential explanatory mixed-methods study with two phases: phase 1: quantitative survey and phase 2: qualitative follow-up interviews.

SETTING

For the quantitative phase, an online survey was launched in March 2021, using Microsoft Forms. For the qualitative phase, in-depth semistructured interviews were conducted via online.

PARTICIPANTS

368 adults over 18 years old living in the UK with at least one long-term condition completed the survey. Interviews were conducted in a subsample of participants from the previous quantitative phase, with 26 people. Data were analysed using thematic analysis.

RESULTS

Responses from the survey showed that people with one long-term condition were significantly more physically active and spent less time sitting, than those with two or more conditions, presenting with significantly higher well-being (p<0.0001), and lower levels of anxiety (p<0.01), and depression (p<0.0001). Interviews found that people developed a range of strategies to cope with the impact of changeability and the consequences of their long-term condition on their physical activity.

CONCLUSIONS

The number of long-term conditions influenced physical activity and how people coped with their condition during COVID-19. Findings will inform policy developments in preparation for future pandemics to support and remain people to remain physically active and mental health.

Effects of high-intensity interval training on depressive and anxiety symptoms in healthy individuals: A systematic review and meta-analysis of randomized clinical trials

Although evidence regarding the effects of high-intensity interval training (HIIT) on mental health has increased in recent years, there is still no consensus regarding the effects of HIIT on the symptoms of depression and anxiety in a healthy population. Therefore, this systematic review aimed to investigate the effects of HIIT on depressive and/or anxiety symptoms in healthy individuals. The following four databases were searched: PubMed, Scopus, Embase, and PsycINFO. Only randomized clinical trials (RCTs) were included. We performed a random-effects meta-analysis based on standardized mean difference (SMD). The risk of bias was assessed using the RoB 2.0 tool, and the certainty of the evidence was evaluated based on recommendations GRADE. Eight RCTs evaluating 471 participants (81% female) were considered eligible for inclusion. The results of the meta-analysis showed that HIIT-based interventions had no significant effect on reducing anxiety (SMD = -0.17; 95% CI: -0.53, 0.19; p = 0.27) and depressive symptoms (SMD = -0.38; 95% CI: -1.06, 0.30; p = 0.17) compared with the passive control group. In conclusion, HIIT does not improve symptoms of depression and anxiety in healthy individuals. This finding is based on evidence of very low certainty. Therefore, the evidence is still not consistent enough to support HIIT as a viable strategy to reduce both outcomes because of the limited number of included studies and the overall quality of evidence.

Clinical value and mechanistic analysis of HIIT on modulating risk and symptoms of depression: A systematic review

Background

The exact causal mechanisms of depression remain unclear due to the complexity of the triggers, which has led to limitations in treating depression using modern drugs. High-intensity interval training (HIIT) is as effective as medication in treating depression without toxic side effects. Typically, HIIT requires less time commitment (i.e., shorter exercise duration) and exhibits pronounced benefits on depressive symptoms than other forms of physical exercise. This review summarizes the risk reduction and clinical effects of HIIT for depression and discusses the underlying mechanisms, providing a theoretical basis for utilizing HIIT in treating depression.

Methods

A database search was conducted in PubMed, Embase, Web of Science, and Scopus from inception up to October 2022. The methodological quality of the included literature was evaluated by the physiotherapy evidence database (PEDro) scale criteria. The review focused on evaluating the changes in depression risk or symptoms of HIIT interventions in healthy individuals, patients with depression, and patients with other disorders co-morbid with depression. Consequently, the mechanisms associated with depression related HIIT were summarized.

Results

A total of 586 participants (52 % female; mean age: 43.58±8.93 years) from 22 studies were included. Implementing HIIT using different exercise types alleviates depressive symptoms in individuals with depression and in individuals with depression who have exhibited comorbidities and reduced depression scale scores in subjects immediately after acute exercise. In addition, the long-interval HIIT and short-interval HIIT in the treatment of patients with cardiovascular or psychiatric disorders may reduce depressive symptoms via complex exercise-related changes on several levels, including by effecting the following measures: releasing monoamines, reducing neuronal death, inducing neurogenesis, modulating the functional homeostasis of the HPA axis, and enhancing the level of inflammation in the body.

Conclusion

HIIT is a relatively safe and effective antidepressant, which may involve multiple neurobiological mechanisms (release of monoamines, reducing neuronal death, inducing neurogenesis, modulating the functional homeostasis of the HPA axis, and enhancing the level of inflammation in the body), thereby reducing the risk or symptoms of depression in participants.

Exercise and Acute Affect

The study of the affective impact of physical activity and exercise has a long and fraught history. In this chapter we outline some of the longstanding issues, in the hopes that research moving forward will be more mindful of these. Included are: (a) what we are actually trying to assess; (b) measurement issues; (c) the timing of affective measurement; (d) research that highlights what we know and don't know; and (e) suggestions for moving forward.

Rates of compliance and adherence to high-intensity interval training: a systematic review and Meta-analyses

BACKGROUND

To determine rates of compliance (i.e., supervised intervention attendance) and adherence (i.e., unsupervised physical activity completion) to high-intensity interval training (HIIT) among insufficiently active adults and adults with a medical condition, and determine whether compliance and adherence rates were different between HIIT and moderate-intensity continuous training (MICT).

METHODS

Articles on adults in a HIIT intervention and who were either insufficiently active or had a medical condition were included. MEDLINE, EMBASE, PsychINFO, SPORTDiscus, CINAHL, and Web of Science were searched. Article screening and data extraction were completed by two independent reviewers. Risk of bias was assessed using RoB 2.0 or ROBINS-I. Meta-analyses were conducted to discern differences in compliance and adherence between HIIT vs. MICT. Sensitivity analyses, publication bias, sub-group analyses, and quality appraisal were conducted for each meta-analysis.

RESULTS

One hundred eighty-eight unique studies were included (n = 8928 participants). Compliance to HIIT interventions averaged 89.4% (SD:11.8%), while adherence to HIIT averaged 63% (SD: 21.1%). Compliance and adherence to MICT averaged 92.5% (SD:10.6%) and 68.2% (SD:16.2%), respectively. Based on 65 studies included in the meta-analysis, compliance rates were not different between supervised HIIT and MICT interventions [Hedge's g = 0.015 (95%CI: - 0.088-0.118), p = .78]. Results were robust and low risk of publication bias was detected. No differences were detected based on sub-group analyses comparing medical conditions or risk of bias of studies. Quality of the evidence was rated as moderate over concerns in the directness of the evidence. Based on 10 studies, adherence rates were not different between unsupervised HIIT and MICT interventions [Hedge's g = - 0.313 (95%CI: - 0.681-0.056), p = .096]. Sub-group analysis points to differences in adherence rates dependent on the method of outcome measurement. Adherence results should be interpreted with caution due to very low quality of evidence.

CONCLUSIONS

Compliance to HIIT and MICT was high among insufficiently active adults and adults with a medical condition. Adherence to HIIT and MICT was relatively moderate, although there was high heterogeneity and very low quality of evidence. Further research should take into consideration exercise protocols employed, methods of outcome measurement, and measurement timepoints.

REGISTRATION

This review was registered in the PROSPERO database and given the identifier CRD42019103313.

High-intensity Interval Training for the Management of Nonalcoholic Steatohepatitis: Participant Experiences and Perspectives

Background and Aims

High-intensity interval training (HIIT) is a therapeutic option for people with nonalcoholic steatohepatitis (NASH). However, the perspectives and experiences of HIIT for people with NASH are unknown, limiting translation of research. We explored the experiences and perspectives of both professionally supervised and self-directed HIIT in people with NASH and evaluated participant-reported knowledge, barriers, and enablers to commencing and sustaining HIIT.

Methods

Twelve participants with NASH underwent 12 weeks of supervised HIIT (3 days/week, 4×4 minutes at 85-95% maximal heart rate, interspersed with 3 minutes active recovery), followed by 12-weeks of self-directed (unsupervised) HIIT. One-on-one, semistructured participant interviews were conducted by exercise staff prior to HIIT and following both supervised and self-directed HIIT to explore prior knowledge, barriers, enablers, and outcomes at each stage. Interviews were audio-recorded, transcribed, coded, and thematically analyzed by two independent researchers.

Results

Four dominant themes were identified: (1) no awareness of/experience with HIIT and ambivalence about exercise capabilities; (2) multiple medical and social barriers to commencing and continuing HIIT; (3) exercise specialist support was a highly valued enabler, and (4) HIIT was enjoyed and provided holistic benefits.

Conclusions

People with NASH may lack knowledge of and confidence for HIIT, and experience multiple complex barriers to commencing and continuing HIIT. Exercise specialist support is a key enabler to sustained engagement. These factors need to be addressed in future clinical programs to augment the uptake and long-term sustainability of HIIT by people with NASH so they can experience the range of related benefits.

Exercise training and resting blood pressure: a large-scale pairwise and network meta-analysis of randomised controlled trials

OBJECTIVE

To perform a large-scale pairwise and network meta-analysis on the effects of all relevant exercise training modes on resting blood pressure to establish optimal antihypertensive exercise prescription practices.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

PubMed (Medline), the Cochrane library and Web of Science were systematically searched.

ELIGIBILITY CRITERIA

Randomised controlled trials published between 1990 and February 2023. All relevant work reporting reductions in systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) following an exercise intervention of ≥2 weeks, with an eligible non-intervention control group, were included.

RESULTS

270 randomised controlled trials were ultimately included in the final analysis, with a pooled sample size of 15 827 participants. Pairwise analyses demonstrated significant reductions in resting SBP and DBP following aerobic exercise training (-4.49/-2.53 mm Hg, p<0.001), dynamic resistance training (-4.55/-3.04 mm Hg, p<0.001), combined training (-6.04/-2.54 mm Hg, p<0.001), high-intensity interval training (-4.08/-2.50 mm Hg, p<0.001) and isometric exercise training (-8.24/-4.00 mm Hg, p<0.001). As shown in the network meta-analysis, the rank order of effectiveness based on the surface under the cumulative ranking curve (SUCRA) values for SBP were isometric exercise training (SUCRA: 98.3%), combined training (75.7%), dynamic resistance training (46.1%), aerobic exercise training (40.5%) and high-intensity interval training (39.4%). Secondary network meta-analyses revealed isometric wall squat and running as the most effective submodes for reducing SBP (90.4%) and DBP (91.3%), respectively.

CONCLUSION

Various exercise training modes improve resting blood pressure, particularly isometric exercise. The results of this analysis should inform future exercise guideline recommendations for the prevention and treatment of arterial hypertension.

Physical activity and exercise for weight loss and maintenance in people living with obesity

Physical activity and exercise training programs are integral part of a comprehensive obesity management approach. In persons with overweight or obesity, exercise training, specifically aerobic (i.e. endurance) training, is associated with significant additional weight loss compared to the absence of training. However the magnitude of effect remains modest amounting to only 2-3 kg additional weight loss on average. Comparable effects have been observed for total fat loss. Exercise training, specifically aerobic training, is also associated with decreased abdominal visceral fat as assessed by imaging techniques, which is likely to benefit cardiometabolic health in persons with obesity. Based on data from controlled trials with randomization after prior weight loss, the evidence for weight maintenance with exercise training is as yet not conclusive, although retrospective analyses point to the value of relatively high-volume exercise in this regard. Resistance (i.e. muscle-strengthening) training is specifically advised for lean mass preservation during weight loss. Given the relatively limited effect of exercise training on weight loss as such, the changes in physical fitness brought about by exercise training cannot be overlooked as they provide major health benefits to persons with obesity. Aerobic, as well as combined aerobic and resistance training, increase cardiorespiratory fitness (VO2max) while resistance training, but not aerobic training, improves muscle strength even in the absence of a significant change in muscle mass. Regarding the overall management strategy, adherence in the long term to new lifestyle habits remains a challenging issue to be addressed by further research.

Analysis of Exercise Intensity Preferences, Tolerance, Competence, and Their Implications for Behavioral Intentions in Fitness Settings

This study aims to comprehensively investigate the interrelationships among exercise intensity preference, tolerance, competence satisfaction, competence frustration, and exercise intentions within the fitness domain. The research involved 114 participants aged 18 to 59 years (M = 33.23; SD = 10.542), with an average height of 166.02 cm (SD = 15.856) and weight of 68.02 kg (SD = 13.658). The path analysis revealed positive correlations among constructs, except for the link between exercise intensity tolerance and competence satisfaction. Notably, exercise intensity preference positively related to competence satisfaction (β = 0.20, CI90% = 0.12, 0.40), while both preference and tolerance were negatively linked to competence frustration (preference: β = -0.27, CI90% = -0.44, 0.03; tolerance: β = -0.17, CI90% = -0.03, 0.24). Competence satisfaction (β = 0.37, CI90% = 0.13, 0.34) and competence frustration (β = -0.29, CI90% = -0.48, -0.09) significantly influenced exercise intentions. An indirect effect existed between exercise intensity preference and intentions (β = 0.11, CI90% = 0.03, 0.21), contrasting with the lack of such effect for intensity tolerance (β = 0.05, CI90% = -0.01, 0.14). Intentions explained 16% of the variance. In conclusion, this study underscores the intricate connections between exercise intensity traits and intentions, shedding light on factors influencing individuals' exercise persistence.

Making a HIIT: Methods for quantifying intensity in high-intensity interval training in schools and validity of session rating of perceived exertion

Using the data from Making a HIIT, this paper aimed to: 1) investigate the different heart rate (HR) quantification methods reported in school-based high-intensity interval training (HIIT) studies; and 2) assess the criterion validity of session rating of perceived exertion (RPE). During an 8-week HIIT intervention, 213 students (13.1 (0.6) years; 46% female) completed 10-minute HIIT workouts during physical education lessons. In total, 1057 HR and RPE measurements were collected across 68 HIIT workouts. For aim 1, the average and peak HR across all participants and workouts were 79% (8%) and 92% (6%) of HRmax, respectively. The average RPE was 6 (2) points on a 10-point scale. An average of 51% of students in a class had an average HR ≥ 80% for each workout. The between-person variation for peak and average HR were 19% and 30% , respectively. Both average and peak HR decreased by 0.5% each week (p < 0.001). To assess aim 2, a within-participant correlation was calculated for the internal training load produced using HR and RPE data. The correlation was 0.39 (p < 0.001), which suggests utility of using RPE when HR is not a viable option.

Addition of high-intensity interval training to a moderate intensity continuous training cardiovascular rehabilitation program after ischemic cerebrovascular disease: A randomized controlled trial

Introduction

Moderate intensity continuous training (MICT) is usually recommended for stroke or transient ischemic attack (TIA) patients. High intensity interval training (HIIT) has emerged as a potentially effective method for increasing cardiorespiratory fitness (CRF) among clinical populations. Its effectiveness remains to be demonstrated after stroke. A combined program of HIIT and MICT was designed to create a realistic exercise program implemented for a clinical setting to help patients become more active.

Purpose

This study aimed to compare the effects of a 6-month exercise program with either MICT only or a combination of HIIT and MICT and a control group in terms of CRF, cardiovascular risk factors, functionality, cognitive function (Montreal Cognitive Assessment) and depression markers (Hospital Anxiety and Depression Scale).

Methods

This randomized controlled trial started with 52 participants (33 men and 19 women, mean age: 69.2 ± 10.7) divided into three groups: HIIT + MICT combined, MICT, and control. Both exercise groups consisted of 4 weekly sessions including supervised and at-home exercise. Outcomes were assessed at T0 (baseline measure), T6 (end of exercise protocols), and T12 (follow-up), 40 participants having completed the 12-month follow-up.

Results

At T6, both HIIT+MICT and MICT programs provided a similar increase of CRF (3 ml·min-1·kg-1) from baseline (p < 0.01), while the control group showed a global slight decrease. Despite some decrease of CRF at T12 compared to T6, improvement persisted 6 months post-intervention (HIIT + MICT: p < 0.01 and MICT: p < 0.05). The control group decreased compared with baseline (p < 0.05). The two exercise programs induced a comparable increase in self-reported physical activity and a decrease in anxiety and depression markers. Participants in HIIT + MICT and MICT programs declared a good degree of acceptability assessed by the Acceptability and Preferences Questionnaire.

Conclusion

A 6-month HIIT + MICT combined program and a standard MICT program induced similar improvements in CRF, self-reported physical activity and anxiety and depression markers among patients with prior ischemic stroke or TIA compared with a control group. These effects appear to persist over time. Addition of HIIT was safe and considered acceptable by participants. Our results do not support any superiority of the combination HIIT + MICT nor disadvantage vs. MICT in this population.